1. Technical Field
The present disclosure relates to an apparatus for surgically treating tissue with a pressurized gas. In particular, the disclosure relates to an apparatus with a mechanism for releasing the gas from a cylinder or tank.
2. Background of Related Art
Surgical instruments are commonly used for procedures such as tissue division, dissection, ablation, coagulating and arresting blood loss in tissue. One type of instrument employs a heated probe to arrest bleeding in a technique called thermic coagulation. Heat may be conducted from a relatively hot probe tip to the tissue to be treated by moving the probe into contact or into close proximity with the tissue. The probe may adhere to the tissue while the tissue is being treated, and thus removing the probe often causes repeat bleeding. Many such probes also produce an undesirable buildup of eschar on or proximate the tip, which detrimentally affects the efficiency of the surgical instrument. Another type of instrument directs high frequency electric current through the tissue to stop bleeding. These instruments typically include at least one electrode for contacting the tissue to be treated to establish electrical communication with the tissue. Again, tissue adherence and eschar buildup may occur with these instruments.
Other instruments achieve coagulation by providing a gas to the atmosphere adjacent the targeted tissue. An ionizable gas, for example argon gas, may be directed toward the tissue past an electrode just prior to exiting a distal end of the instrument. An electrosurgical current may be conducted to the tissue through ionized conductive pathways in the gas without requiring direct contact between the electrode and the tissue. Providing an atmosphere of ionized gas may also be beneficial, for example, since the gas displaces oxygen from the area and reduces oxidative stress of the tissue.
The gas may be held in pressurized cylinders or tanks until a surgeon is ready to begin treatment. Relatively large cylinders may be fixed in one location or may be disposed on a movable cart in the operating room. A gas supply hose fluidly connects the remote cylinders to the instrument. Other configurations provide for a relatively small cylinder to be housed within a receptacle defined in a hand-held instrument. In either case, a seal in the cylinder may be ruptured to initiate the flow of the gas to the instrument. A substantial force, about 60 lbs in some instances, may be required to rupture the cylinder seal. Providing such a force may be difficult or distracting for a surgeon or support clinician in an operating environment.